I heard a Smokey Robinson and The Miracles song last week that interested me because I had never heard it in Detroit (and I grew up there) and because it sounded like it might be about Paul and his song, "Yesterday."
The song is "Yester Love", recorded on December 12, 1967 and released May 13, 1968. I probably never heard it in Detroit because it was recorded for Motown's European label, Tamla. Tamla-Motown records were released in England by Parlophone, who recorded The Beatles' records.
Smokey Robinson used his usual wordplay on the word yesterday. One of the lines of the song reads: Today I'll be on my way to love my yester love.
Remember Paul's song, "I'll Be On My Way"?
I thought there might be backmasking on "Yesterlove" and, in fact, there is:
In the reversed song at:
0:08-0:18: Say goodbye to me (x3)
1:06-1:12: Say goodbye to me (x2)
1:36-1:43 Say goodbye to Mickey (x2)
This isn't Smokey Robinson wanting to say goodbye to The Miracles, because, from what I've read, he didn't start wanting to retire from performing until 1969. And, true, he doesn't say Paul, but because they released it on the Tamla label meant for an English audience, it might have been a message about the real Paul and our Paul.
Note: To let people know that The Miracles wanted people to understand there was intentional backmasking on the song, the beginning chords on the reversed song are the same as the ending chords on the forward song: a clever way to alert people of the backmasking.